TITLE: GCN CIRCULAR NUMBER: 11902 SUBJECT: GRB 110407A: Swift-BAT refined analysis DATE: 11/04/07 23:10:05 GMT FROM: Scott Barthelmy at NASA/GSFC T. N. Ukwatta (MSU), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC), D. M. Palmer (LANL), T. Sakamoto (GSFC/UMBC), M. Stamatikos (OSU), J. Tueller (GSFC), C. W. Wolf (PSU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+800 sec from recent telemetry downlinks, we report further analysis of BAT GRB 110407A (trigger #450884) (Wolf, et al., GCN Circ. 11894). The BAT ground-calculated position is RA, Dec = 186.022, 15.726 deg, which is RA(J2000) = 12h 24m 05.3s Dec(J2000) = +15d 43' 33.2" with an uncertainty of 1.5 arcmin, (radius, sys+stat, 90% containment). The partial coding was 77%. The mask-weighted light curve shows several overlapping peaks starting at ~T-10 sec, peaking at ~T+15 sec, and ending around T+275 sec. T90 (15-350 keV) is 145 +- 15 sec (estimated error including systematics). The time-averaged spectrum from T-2.9 to T+158.8 sec is best fit by a power law with an exponential cutoff. This fit gives a photon index 0.73 +- 0.64, and Epeak of 57.9 +- 15.1 keV (chi squared 46.5 for 56 d.o.f.). For this model the total fluence in the 15-150 keV band is 1.7 +- 0.2 x 10^-6 erg/cm2 and the 1-sec peak flux measured from T+27.64 sec in the 15-150 keV band is 0.5 +- 0.1 ph/cm2/sec. A fit to a simple power law gives a photon index of 1.73 +- 0.12 (chi squared 55.6 for 57 d.o.f.). All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/450884/BA/